Hey Calvin
You have gotten a great finish on both models!
The mud effect on the M4A1 looks super, as does the hedgerow prong.
I really like the Olive Drab shade you have used.
There are a couple of things you could maybe get onto next time? The pistol ports (shell ejection ports) on the left of each turret were more than usually blended in to the surrounding turret side. This simply requires a 'worm' of putty to be attached on each side and the bottom, and then blended so there is a smooth transition up onto the port's frame.
Also, I don't think you would find a water cooled .30cal mounted on a Sherman. It contained a hose and water container with coolant, which isn't present on your model. They were one heavy bugger!
The second looks to be the M19
19A4.
The periscope housing on the commanders hatch still looks to be oversized as per the Tamiya 1/35 version. This would benefit from an aftermarket periscope set, which can also include PE housings of much better thickness.
You have gone to the lengths of using aftermarket equipment/soft armour, but I think in future the actual tank would benefit from periscope guards, especially in the M4A1 timeframe?
I don't own a 1/48 scale Sherman, but did the kit come with the .50cal barrel clamp? It would be present on the opposite side of the commanders hatch to the MG, in that little slot...
I hope you view these points as constructive, which is what they are intended to be
Cheers
Brad